# Copyright (C) 2012 Nippon Telegraph and Telephone Corporation. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or # implied. # See the License for the specific language governing permissions and # limitations under the License. import struct from . import packet_base from . import arp from . import ipv4 from . import ipv6 from . import lldp from . import slow from . import llc from ryu.ofproto import ether class vlan(packet_base.PacketBase): """VLAN (IEEE 802.1Q) header encoder/decoder class. An instance has the following attributes at least. Most of them are same to the on-wire counterparts but in host byte order. __init__ takes the correspondig args in this order. ============== ==================== Attribute Description ============== ==================== pcp Priority Code Point cfi Canonical Format Indicator vid VLAN Identifier ethertype EtherType ============== ==================== """ _PACK_STR = "!HH" _MIN_LEN = struct.calcsize(_PACK_STR) def __init__(self, pcp=0, cfi=0, vid=0, ethertype=ether.ETH_TYPE_IP): super(vlan, self).__init__() self.pcp = pcp self.cfi = cfi self.vid = vid self.ethertype = ethertype @classmethod def get_packet_type(cls, type_): """Override method for the Length/Type field (self.ethertype). The Length/Type field means Length or Type interpretation, same as ethernet IEEE802.3. If the value of Length/Type field is less than or equal to 1500 decimal(05DC hexadecimal), it means Length interpretation and be passed to the LLC sublayer.""" if type_ <= ether.ETH_TYPE_IEEE802_3: type_ = ether.ETH_TYPE_IEEE802_3 return cls._TYPES.get(type_) @classmethod def parser(cls, buf): tci, ethertype = struct.unpack_from(cls._PACK_STR, buf) pcp = tci >> 13 cfi = (tci >> 12) & 1 vid = tci & ((1 << 12) - 1) return (cls(pcp, cfi, vid, ethertype), vlan.get_packet_type(ethertype), buf[vlan._MIN_LEN:]) def serialize(self, payload, prev): tci = self.pcp << 13 | self.cfi << 12 | self.vid return struct.pack(vlan._PACK_STR, tci, self.ethertype) vlan.register_packet_type(arp.arp, ether.ETH_TYPE_ARP) vlan.register_packet_type(ipv4.ipv4, ether.ETH_TYPE_IP) vlan.register_packet_type(ipv6.ipv6, ether.ETH_TYPE_IPV6) vlan.register_packet_type(lldp.lldp, ether.ETH_TYPE_LLDP) vlan.register_packet_type(slow.slow, ether.ETH_TYPE_SLOW) vlan.register_packet_type(llc.llc, ether.ETH_TYPE_IEEE802_3)